Wet suits worn by surfers, divers, sailboarders and other water sports enthusiasts are normally made of closed cell foam elastomer, which permits water to flow into the wet suit through sleeve, ankle and neck openings but inhibits the circulation of such water due to the tight-fitting nature of the suit. The water that has entered the suit thereby forms a thin, non-circulating film between the body of the diver and the suit. This film of water is heated by the body of the diver and, in effect, forms a layer of thermal insulation. Because the thermal insulating property of the wet suit can only be achieved by inhibiting the circulation of the film of water, the suit must be made to tightly fit the body of the diver.
In particular, achieving a tight fit with boots used in underwater diving and other aquatic activities is extremely difficult because the boot must have an opening large enough to permit insertion of the foot yet fit tightly about the ankle. The patent to Stockli et al., U.S. Pat. No. 4,294,022 is exemplary. The difficulty with slip-on boots of the foregoing type is that if they are constructed tight enough to inhibit water circulation inside the boot, they are very difficult to put on and to take off due to the width of the foot. Additionally, the stretching of the elastomeric material that occurs whenever the slip-on boot is removed or applied can lead to permanent deformation or tearing of the material.
Boots of this character have been constructed with zippers, laces or other fasteners to permit easy application and removal. However, these constructions do not adequately inhibit water circulation inside the boot and consequently, the utility of the boots have been sacrificed in favor of easy application and removal.